1. Field of the Invention
The present invention relates to the field of consoles, more particularly to the field of supporting a heat sink used to cool a console processor.
2. Description of Related Art
A modern computer processor, also known as central processing unit (“CPU”), tends to generate a fair amount of heat when in operation. The majority of this heat is caused by the electrical leakage of the transistors that make up a CPU. While attempts have been made to reduce the heat output of CPU's, in general the attempts have been unsuccessful.
The lack of success is because number of transistors on a CPU has increased from about 6000 transistors on an Intel® 8080 in 1974 to more than 50 million resistors on modern CPU's. The increase in the number of transistors (and the speed at which they work) has provided a significant increase in performance. Current CPU's are more than a 10000 times faster than the initial models. However, this increase is performance has come at a cost, a significant increase in thermal output.
When a transistor changes states, a small amount of electricity is leaked and this leakage generates heat. The decrease in the size of transistors has helped somewhat but the remarkable increase in the number of transistors and the speed of operation has overcome any reductions provided. Thus, a modern CPU, while about the size of a thumbnail, can be expected to generate more than 50 watts of heat and some CPU's generate more than a hundred watts of heat. With the relatively small size of the CPU, this heat generation has become a significant problem. A maximum die temperature for a silicon based CPU is somewhere in the range of 90 C, however a processor can be expected to have a relatively short life if operated at such a high temperature.
Therefore, given the fact that the modern CPU's will generate significant amounts of heat, some method is needed to remove the heat from the CPU so the CPU does not fail prematurely. As is known, there are three basic mechanisms for transferring heat, conductive heat transfer, convection heat transfer, and radiation heat transfer. Obviously, it would be preferable to not use a method that is extremely expensive or loud. Noise is especially important for consoles use to play games because background noise detracts from the immersive quality of a game.
One common method is to increase air flow across the CPU. By increasing the number of fans, it is possible to generate additional air flow and more quickly remove heat from the CPU. However, the generation of increased airflow has a drawback, additional noise is generated. Thus, while it is now common to include multiple fans to cool a CPU, it would be preferable to use lower speed fans.
In addition to increasing the flow of air over a CPU, it is has become standard practice to mount a heat sink to the CPU to help transfer heat away. As is known, a heat sink is tightly mounted to the CPU and the heat sink conducts the heat away from the CPU and air flow across the heat sink removes the heat via convection. Typically a CPU is attached to a substrate that is mounted to a printed circuit board (“PCB”) and a heat sink is mounted to the CPU so that the heat generated by the CPU enters the heat sink and is conducted away. Typically the heat sink is mounted to the CPU via a frame that is mounted on the PCB and the frame/PCB combination supports the heat sink during a shock event. While heat sinks initially were made of aluminum, to improve conductivity, heat sinks are increasingly made of copper or other materials that are better conductors of heat than aluminum. In addition, heat sinks are usually designed with fins so that the heat transferred to the heat sink by conduction can be readily convected away from the heat sink by the flow of air across the fins.
To allow the heat sink to work effectively, however, it is necessary to tightly mount the heat sink to the CPU. Within reason, the tighter the connection, the better the heat transfer. To provide a tight connection, it is common for a heat sink to include a clip, typically made of plastic, which extends down the middle of the heat sink. The clip fastens the heat sink to the frame and ensures the heat sink and CPU remain under a compression load (i.e. have a tight connection). The clip is typically made of plastic and can provide a reasonable amount of force so as to ensure the heat sink is tightly held to the CPU. This has the unfortunate effect, however, of placing a relatively poor conductor (the plastic clip) over the hottest part of the heat sink. And even if the clip was made of metal it would still prevent the use fins across a portion of the surface of the heat sink.
In addition, mounting the heat sink to the frame that is supported by the PCB forces the PCB to support the mass of the heat sink. This can be problematic because if the console is dropped the PCB acts as spring damper for the heat sink and will tend to flex. Such flexing can cause the PCB to fail, especially when using leadless solder because leadless solder, while more environmentally friendly, tends to crack more readily than lead based solders. Thus, it would desirable to use a heat sink mounting system that can avoid placing excessive forces on the PCB while still allowing the heat sink to tightly press against the CPU.
Thus, while current systems of removing heat generated by the CPU have been somewhat effective at preventing the CPU and the surrounding components from failing prematurely due to heat or, additional improvements to the process are needed.